 offers the promise of new techniques and new technologies in pharmaceuticals, materials, manufacturing, and microgravity studies are a key component of fundamental research on the shuttle today. But vibrations from shuttle maneuvers, operating equipment, even movement of the crew within the cabin can mimic the effects of gravity. Vibrations set up to take advantage of a weightless environment are subtly affected, yet when researchers know the strength and frequency of these vibrations, they can determine and account for the forces acting on these microgravity experiment samples. The Space Acceleration Measurement System, or SAMS, developed by the Lewis Research Center measures, conditions, and records forces of low gravity accelerations on the shuttle. From the United States and international microgravity missions to the Space Lab Life Science Series, SAMS has provided vital information on shuttle experiments. This information guides scientists to a better understanding of the effects of microgravity accelerations on these experiments. The SAMS hardware consists of a main signal processing unit and three remote triaxial sensor heads. By mounting a SAMS sensor head on or near an experiment, the accelerations affecting the experiment can be sampled directly. The triaxial sensor heads detect accelerations along three orthogonal axes. These inertial sensors measure positive and negative accelerations over a specified frequency range. SAMS has provided researchers with measurements of these accelerations since its first flight in June of 1991 aboard STS-40, the Space Lab Life Science Series 1 mission. Since that first mission, the unit has flown in a variety of locations, including both the Space Lab's center aisle and its mid-deck experiment rack, the shuttle's mid-deck, the spacehab, and the cargo bay. To accommodate the different environments of these locations, SAMS offers three configurations to researchers. In the Spacehab's center aisle configuration, the SAMS unit allows the flight crew access to the optical disks, which they can periodically rotate or exchange to provide unlimited data recording. Also accessible are the control switches and indicators of the main unit located on the front panel. In the mid-deck configuration, the unit is mounted either in a SMIDEX rack or in place of a stowage locker. It is fastened to a bulkhead by a mounting plate the mission office provides. Disks and controls are accessible throughout the mission. The triaxial sensor heads are mounted either prior to launch or by the flight crew once in orbit. Flight crew members can place the sensor heads at predetermined locations to accommodate the needs of the experimenter. The sensor heads can be mounted directly on the experiment or up to a maximum distance of 20 feet from the main unit. The sensor head cables can be easily connected to the rear right side of the main unit in the center aisle configuration and to the unit's faceplate when at mid-deck. The last configuration for the SAMS unit is known as MPES for mission peculiar experiment support structure. Here the unit is placed in the cargo bay, inaccessible to the flight crew. The MPES main control unit and data storage unit are safely enclosed for operation in this harsh environment. In this configuration, the SAMS unit can retain 0.8 gigabytes of data. Raw data in this configuration can be down-linked to the Payload Operations Control Center or POC. This provides researchers with the opportunity to monitor and analyze data displays in a time frame which approaches real-time. Three switches, power, data record and disk change are located on the control panel. Five indicator lights or LEDs are also located on the control panel. The LEDs are designed to confirm basic operating functions of the SAMS unit. Additionally, they will indicate certain failures of the SAMS unit should they occur. Using normal operations, the tri-color LEDs on the recording drive will pulsate from yellow to red. Yellow indicates that the optical disk is spinning in the disk drive, while red indicates that the drive is reading from or writing to the optical disk. This concludes Module 1, the background and system familiarization of the space acceleration measurement system. In this module, we will demonstrate the nominal operations of the SAMS unit. First, you need to un-stow the optical disks. Rotate the door screws counter-clockwise to open the drive doors. Next, rotate the disk ejection levers counter-clockwise. Stow the dummy disks and un-stow two blank disks. Rotate the blank disks side A up into drives 1 and 2, making sure that the disks lock into place. Then rotate the disk ejection lever clockwise until they are pointing up, with respect to the top plate of the unit. To activate the SAMS unit, turn the power on. Verify that the power indicator light is green. At the mission elapsed time, the drive 1 full light and the drive 2 full light should be lit during initialization. Allow two minutes for the initialization process to be completed. After the initialization process is complete, and the drive 1 and drive 2 indicator lights are off, notify the pot that the power is on and note the mission elapsed time. After allowing the unit to warm up for 15 minutes, you are now ready to operate SAMS. First close the disk drive doors and rotate the screws clockwise to the lock position. Then turn the data record switch on. Verify that the data record light is on and record the MET. After three minutes, verify that the drive 1 and drive 2 full lights are off. Verify the pock that the SAMS unit is recording data and indicate the current MET. Before you rotate the disk in drive 1, check to see if the system error light is on. This should not occur during normal operations, but if it does, consult the pock. Verify that the drive 1 full light is solid yellow. Next rotate the drive door screws counterclockwise. Rotate the disk ejection lever counterclockwise to eject the disk from drive 1. Then log the mission elapsed time and the drive number on side A. Insert the disk side B facing up into drive 1 until the disk locks into place. Rotate the disk ejection lever clockwise pointing up. Tongue the disk change switch momentarily. After three minutes, the drive 1 full light should turn off. Verify that the drive 2 full light is also off. Close the drive door and rotate the screws clockwise to the lock position. Notify the pock that you have completed disk rotation steps 4 through 7. To rotate the optical disk in drive 2, simply repeat the procedure we just demonstrated. Before exchanging the disk in drive 1, check to see that the drive 1 full light is on. Next rotate the drive door screws counterclockwise. Then eject the disk. Log the MET and drive number on the disk side B. Stow the full disk and unstow a blank disk. Now insert the blank disk side A facing up into drive 1 until it locks into place. Turn the disk ejection lever clockwise. Press the disk change switch momentarily. Allow up to three minutes for the drive 1 full light to turn off. Then close the drive door and rotate the screws clockwise to lock. Notify the pock that you have completed replacing the disk in drive 1. To exchange the disk in drive 2, repeat the procedures just demonstrated. To deactivate the SAMS unit, turn off the data record switch. Wait two minutes and verify that the data light is off. Next turn the power switch off. The power indicator light should extinguish. To stow the disks, turn the drive door screws counterclockwise. Now rotate the disk ejection levers counterclockwise to eject the disks. Log the MET and drive number on the disk label. Stow both disks. Unstow the two dummy disks and insert them into drive 1 and drive 2 making sure they lock into place. Turn the disk ejection levers to the locked position. Close the disk drive doors and rotate the screws clockwise so the doors are locked. To check the status of the SAMS unit, turn the door screws counterclockwise. At the specified intervals, voice the status of the five control panel lights and the two disk drive lights. Close both drive doors and turn the screws clockwise to the locked position. Alternate procedures for operation of the SAMS unit are utilized only when one drive has failed. Rotation and exchange of the optical disk is performed in the same manner demonstrated for nominal operation with one notable exception. For single drive operation of SAMS, the drive that is non-operational is put on standby for the duration of the mission. Also during rotation or exchange, the recording of data on the operational drive is temporarily aborted in order to eject the disk without damage to the recorded data. For example, if disk drive 2 fails, place it in the standby position by rotating the disk ejection lever to the 9 o'clock position. The lever should remain in this position for the duration of the mission. Then to temporarily abort drive 1, wait until the tricolor LED flashes from red to yellow. Then turn the drive 1 disk ejection lever clockwise to the 1 o'clock or abort position. This concludes module 2, the nominal and alternate procedures for the space acceleration measurement system. In module 3, we will briefly review malfunctions of the SAMS unit and the procedures to follow should a malfunction occur. If the power light does not illuminate when power is initially applied to the SAMS unit, perform malfunction procedure 1. To determine the cause of this condition, you would cycle the power and examine the status of certain LEDs. The SAMS unit could be in one of three states. The power light is transient. The power light has failed, or there has been a system power failure in the unit. If the unit is in one of the first two conditions, it can still be operational. However, if it is determined that the unit is in the third condition, a power system failure, then it would remain non-operational for the duration of the mission. After power is applied to SAMS, the initialization process begins. The drive full lights will illuminate to indicate the start of the initialization process and extinguish after the process is complete. This takes about two minutes. If after two minutes, one or both of the drive full lights are on, solid or blinking, then perform malfunction procedure 2. If this happens, one of the following has occurred. A disc may not be seated properly. Receding the disc would eliminate the error. The discs may be faulty. Rotating or exchanging them would solve the problem. The unit may be recording on a single drive only. If this occurs, refer to the alternate procedures described in module 2. The system may have failed, and again will be non-operational for the duration of the mission. After the initialization of SAMS and a 15-minute warm-up period, the data record switch is ready to be enabled. If the data record switch is thrown and the data record light does not illuminate, perform malfunction procedure 3. One of three errors has occurred. The data record switch is faulty. The data record light could have failed. There is an uncorrectable fault, in which case the unit will be non-operational for the duration of the mission. When one side of an optical disc is full, the drive full light corresponding to that disc will illuminate. The time it will take to fill one side of a disc is predetermined based on the frequencies of the triaxial sensor heads. If the drive full light does not illuminate as scheduled, perform malfunction procedure 4. In this case, the drive may have had a previous malfunction and has corrected itself, thus becoming operational again. It may also have prematurely quit recording on the drive that was scheduled to be full and is now recording on the other drive. Finally, again, there may have been a system malfunction that could possibly be corrected after consulting the POC. Following rotation or exchange of a full disc and the disc change switch having been toggled, it will take up to three minutes for the corresponding drive full light to extinguish. If after three minutes the corresponding drive full light fails to extinguish, perform malfunction procedure 5. This could indicate that the disc is not seated properly and may have to be receded. The disc may be faulty and may have to be rotated or exchanged. There may also have been a disc drive failure, in which case the alternate procedures would be implemented. At any time during normal operation of SAMS or after any crew interface with SAMS, one or both of the drive full lights may suddenly begin to blink. If this happens, perform malfunction procedure 6. This indicates that the corresponding drive has failed, either temporarily or permanently. If the drive has temporarily quit recording, the malfunction can be corrected. However, the drives will now be out of sequence. The system error light is another indicator of a malfunction. If this LED should illuminate, perform malfunction procedure 7. This indicates that there are 30 minutes or less of recording time available on both optical discs. Note that the system error light will not come on alone. Either one or both of the drive full lights will also be illuminated. If only one drive full light is on, the unit is still able to record data. If both drive full lights are on, the unit is not recording and valuable data is being lost. When you are either rotating or exchanging an optical disc, there is a possibility that the disc will not eject from the drive. If this should happen, perform malfunction procedure 8. The disc may not be seated properly in the drive. Receipt the disc. If the disc will not eject at all, use needle nose pliers to extract the disc. If you cannot retrieve the disc with the pliers, the disc has jammed or the disc ejection system has failed. During single drive operation, the drive full lights may illuminate. If this happens, perform malfunction procedure 9. This could indicate that the disc in the functioning drive is faulty. It could also indicate that the previously faulty drive has corrected itself and is now functioning properly. If this is the case, the disc in the previously faulty drive is full and needs to be rotated or exchanged and the alternate procedures for single drive operation would no longer be necessary. This concludes the third and final module of this video. If you have any questions, please review the appropriate module. And good luck on your upcoming shuttle flight.